The application is related to two other applications entitled (1) Press with Ejector Device for Different Ejector Strokes, whose inventors are Ekkehard Kxc3x6rner and Martin Dxc3x6ringer, Ser. No. 09/629,185, and (2) Press Product line, whose inventors are Ekkehard Kxc3x6rner and Martin Dxc3x6ringer, Ser. No. 09/629,185.
This application claims the priority of 199 35 655.6, filed on Jul. 29, 1999, the disclosure of which is expressly incorporated by reference herein.
The present invention concerns a press which is a member of a press production series and has production series, particularly for massive forming, with a machine frame, with a ram which is guided journalled and disposed for attachment of a first tool component, with a ram drive which is positioned on the machine frame and presets a path-time trace of the ram and which comprises at least one electric motor and at least one eccentric shaft connected to one another via a drive means, and with a table which is positioned opposite to the ram on the machine body and is disposed for attachment of a second tool component.
Mechanical presses having varying stroke speeds corresponding to the task for which they are used are often utilized, particularly for massive forming. In addition, depending on the operating conditions, varying path-time curves of the ram motion may be desired.
A toggle drive or another type of lever drive connecting a continuously rotating eccentric with the ram is often used in this type of press as a mechanical ram drive. The eccentric shaft is connected with the drive motor via a step-down gear with so that the speeds match. Various path-time traces and stroke speeds can be attained with different drive configurations. This represents a significant expense in manufacturing technology.
A mechanical press with a crank-toggle drive is known from DE 2127289 which has two eccentrics positioned at fixed offset angles to one another and two separate connecting rods. The eccentric shaft is connected with a cogwheel which meshes with the pinion of a drive motor. The press does not provide, however, for changing gear ratios.
An object of the present invention is to reduce the expenditure for the production of presses with varying stroke speeds.
According to the invention, various presses are combined into a press production series, within which the presses only vary in regard to the configuration of their ram drives. These include a step-down gear and a gear to transform rotational motion into linear motion. The ram drives are preferably driven from drives which are uniform within the press production series, e.g., in the form of uniform clutch-brake combinations. This is made possible by providing that all presses in the series do not exceed a given maximum eccentric torque. This becomes possible when the gradient of the path-time traces of the ram motion when approaching bottom dead center does not exceed a given limiting value. This limiting value is preferably uniformly determined for all presses of a series.
Matching of different stroke speeds is possible through varying gear systems which have uniform connecting dimensions within the press production series. They are preferably realized as planetary gears with uniform connecting dimensions. The planetary gears can be driven by the electric motor via a belt drive or another type of drive which is uniform within the press production series. The uniform connecting dimensions allow the use of uniform press bodies, press heads and similar items.